# Climate Change Questions **URL:** \ **Category:** Factual Questions\ **Created:** [June 15, 2017, 3:33am UTC](https://boards.straightdope.com/t/climate-change-questions/789010 "2017-06-15T03:33:07Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Reddy\_Mercury](https://avatars.discourse-cdn.com/v4/letter/r/43a26b/32.png) [@Reddy\_Mercury](https://boards.straightdope.com/u/Reddy_Mercury)\ **Post date:** [June 15, 2017, 3:33am UTC](https://boards.straightdope.com/t/climate-change-questions/789010/1 "2017-06-15T03:33:07Z")
If you accept Climate Change, you know 1. Africa and the Middle East will be uninhabitable 2. Many coastal cities and countries will be underwater, lost forever. My questions are: 1. What will happen to the great monuments of history in Africa and the Middle East such as the Pyramids post Climate Change? 2. How long will it take for the effects of Climate Change to wear off - to go back to say, today’s current climate as the ‘norm’? 3. Can Sea-Walls potentially save coastal cities such as New York, New Orleans, Venice, and coastal countries such as Italy and Ireland, or are they going to be lost forever? ---
**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\ **Post date:** [June 15, 2017, 3:45am UTC](https://boards.straightdope.com/t/climate-change-questions/789010/2 "2017-06-15T03:45:46Z")
Time for one of my favorite sites! > **[Lowest Land Points Below Sea Level Map | Depression Elevations](https://geology.com/below-sea-level/)** > > Visit the ten basins with the lowest elevations below sea level - Geology.com At 3-4 meters of sea rise, which is what they’re predicting if most of Antarctica melts (as opposed to 1 meter in the next century if only some of it melts, which is more likely), any place that’s currently threatened by rising water is history: Venice, Amsterdam, New Orleans. Also, the SF Bay Area is going to have major problems because the main highway around the bay is built right by the water, so that’s gone. Both major airports are under water, and the San Joaquin Valley become the San Joaquin Sea, which will be problematic for anybody planning on growing anything but kelp. Also, the main water supply for San Francisco passes through what will be part of the new sea, so they’ll have to come up with a new water supply for most of the Bay Area (I’m from the Bay Area, so this is kind of a focus for me). In order for most coastal cities to be washed away, pretty much all the ice on the planet is going to have to melt, and by that point, we’re talking about enough of a change in climate that we have no idea what the weather effects are going to be… it could be one big hurricane all summer, and one big snow storm all winter, pretty much anywhere. ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [June 15, 2017, 5:09am UTC](https://boards.straightdope.com/t/climate-change-questions/789010/3 "2017-06-15T05:09:36Z")
> [@Reddy\_Mercury](#): > > If you accept Climate Change, you know > > 1. Africa and the Middle East will be uninhabitable > > 2. Many coastal cities and countries will be underwater, lost forever. Even if you don’t accept Climate change - Africa and Middle East will be uninhabitable in the future. Eventually the earth will become uninhabitable and gobbled up by the sun. 1. Many coastal cities and countries will be underwater, lost forever. This has already happened in the past. Google : Dunwich, Ravenser Odd, Sarah Ann Island, Jorsand, Strand … I am a believer in Climate Change, however most models are partially validated and their prediction capabilities are in infancy. ---
**Author:** ![Marci\_Al](https://avatars.discourse-cdn.com/v4/letter/m/e47c2d/32.png) [@Marci\_Al](https://boards.straightdope.com/u/Marci_Al)\ **Post date:** [June 15, 2017, 6:22am UTC](https://boards.straightdope.com/t/climate-change-questions/789010/4 "2017-06-15T06:22:28Z")
You have climate change, then you have global warming, and then you have sea level rise. One is not necessarily a subset of the other (starting from the left.) It’s almost impossible to say there is no such thing as climate change. You see how dynamic the atmosphere is and micro-changes caused by cultural factors (humans) are so prevalent people often mistake them for global change. Examples of micro-changes are increased flooding with increased built-up in a given area, increased average temperature due to removal of foliage and exposed soil (again just in that given area,) poor air quality. Is there really a global warming? Geologists know average temperatures happen in several cycles, from thousands of years, to tens of thousands. It’s hard to measure the greenhouse effect because you have to factor out the effects of the biggest greenhouse gas of all: water. Measuring the effects of CO2, methane, etc. takes a lot of creativity. Sea floor rising? Again recorded geologically but many of these episodes are in cycles millions of years long. But you have the sheer math of the effects of polar ice melt. But maybe a scientist who does the actual research in this could enlighten us some more. Your questions regarding saving low-lying cities are in the realm of engineering, not climatology. ---
**Author:** ![ticker](https://avatars.discourse-cdn.com/v4/letter/t/d07c76/32.png) [@ticker](https://boards.straightdope.com/u/ticker)\ **Post date:** [June 15, 2017, 8:42am UTC](https://boards.straightdope.com/t/climate-change-questions/789010/5 "2017-06-15T08:42:46Z")
> [@Reddy\_Mercury](#): > > 1. How long will it take for the effects of Climate Change to wear off - to go back to say, today’s current climate as the ‘norm’? According to [The Guardian](https://www.theguardian.com/environment/2012/jan/16/greenhouse-gases-remain-air) > [@](#): > > The lifetime in the air of CO2, the most significant man-made greenhouse gas, is probably the most difficult to determine, because there are several processes that remove carbon dioxide from the atmosphere. Between 65% and 80% of CO2 released into the air dissolves into the ocean over a period of 20–200 years. The rest is removed by slower processes that take up to several hundreds of thousands of years, including chemical weathering and rock formation. This means that once in the atmosphere, **carbon dioxide can continue to affect climate for thousands of years**. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [June 15, 2017, 11:47am UTC](https://boards.straightdope.com/t/climate-change-questions/789010/6 "2017-06-15T11:47:16Z")
Re: Africa and the ME becoming uninhabitable. We don’t know for sure about how the climate is going to change for most regions of the globe. (The polar regions we do know for sure the direction.) The feedback mechanism between a warming atmosphere and jet streams is poorly understood. A region like N. Africa, which is incredibly dry, was much greener not that many thousands of years ago due to the change in wind patterns. While unlikely, we can’t rule out that those wind patterns might return and N. Africa gets more rain and gets greener again. Similarly the effects on monsoons are hard to predict. Some might get a lot longer, harsher dry monsoon seasons and others will get longer, wetter wet monsoon seasons. What areas will get what we won’t know until it happens. Note that while the predictions of warming polar regions are being proven true in intensity, they are way off in timing. The rate of warming is much faster than most people were predicting 20 years ago. Effects are still being discovered that play a big role in the feedback loop of the warming. And the polar regions are simpler to model than tropical regions. It’s also not at all clear at what time a tipping point will be reached when there is little humans can do to revert things back to where they were. We might be very close to that point now. ---
**Author:** ![puddleglum](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puddleglum/32/137_2.png) [@puddleglum](https://boards.straightdope.com/u/puddleglum)\ **Post date:** [June 15, 2017, 3:58pm UTC](https://boards.straightdope.com/t/climate-change-questions/789010/7 "2017-06-15T15:58:05Z")
1. The pyramids are just big stacks of rock, they do not need maintenance. Nothing will happen to them. Other monuments might get covered with sand if they are not maintained. 2. In terms of ocean levels, the guesses are around 1,000 years. 3.Rotterdam has built a surge barrier, as has Venice, and New Orleans. It can be done. ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [June 15, 2017, 5:56pm UTC](https://boards.straightdope.com/t/climate-change-questions/789010/8 "2017-06-15T17:56:45Z")
Depends how much the water rises, as Ethilrist discusses. At 1m - some regional catastrophe. There’s usually about more than 3 feet between current sea level and structures. Problems will be more catastrophic in Hurricane Sandy situations, where water surges well above normal. As time goes on, more and more cities will compensate for that with dams and barriers, or by closing off certain flood-prone areas. Countries like Netherlands and Bengaladesh will have the bigger challenge, as will islands - I’m thinking of some low-lying pacific islands, and the Maldives where the 2006 tsunami went across the island basically flooding everything. At 3 - 4M, things get very serious. Many fairly safe areas of cities are flooded, the coastline changes, the ecology of coastlines also changes - dead waterlogged trees instead of sandy beaches, etc. However, the Egyptian pyramids for example are up on a limestone shelf well above the city of Cairo (and suburb or Giza) which itself is about 60 or more miles upriver from the sea. As long as climate change does not bring pounding torrential rains every day, they will survive. The bigger catastrophe would be the Nile delta. It’s a vast fertile area that feeds a substantial portion of Egypt. If much of it is flooded or regularly washed with salt water, things will be worse. venice has surge gates, but they are for occasional storms, not to be a permanent dyke. Rivers empty into the lagoon. That water would have to be pumped out somehow… eventually a losing proposition. I’ve walked across the Lido - it may be a block for storm surges, but I don’t recall it being very high - so it’s not a dam to protect Venice from 3m of higher water. I’ve been in Venice During aqua alta, and without those barriers they would get a foot or two of water in Piazza San Marco, the lowest area, already. Building a 20-foot dam around everything, several dozen miles, would be prohibitively expensive. Even something like the Statue of Liberty - yes, it’s on a pedestal uphill, it should be fine from 1m, but at 3-4m it’s probably a small island or concrete pier rising out of the bay. The big problem is - what will be protected and how? There is so much that would need protecting, not just from 3m of high water, but from the potential storm surges that would result with a higher water level. 4m raised sea level means potential surges 6 or 7m above current sea level. Who would want to live behind that wall in active weather areas? As for “uninhabitable”, that depends on weather trends. Would stronger warming imply bigger clouds, heavier rain, and more cloud cover mitigate temperatures? The same sunshine that gives us 50C or 130+F temperatures in India or Saudi Arabia does not seem to be anywhere near as serious in Brazil, for example. I’m a bit of a skeptic on global warming. Check the latest sunspot data, and we seem to be heading to a global low and another little ice age. We’re also due for a real ice age anytime in the next millennium or three. What humans can do is paltry compared to mother nature. However, pretending that dumping huge amounts of CO2 in the atmosphere and ignoring the consequences because “we can’t be sure” is certainly not a clever move. There’s only one way to find out for sure what will happen, and is it a good idea to try to find out? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 15, 2017, 6:21pm UTC](https://boards.straightdope.com/t/climate-change-questions/789010/9 "2017-06-15T18:21:14Z")
And yet, despite what the Sun is doing, we’re _still_ warming. Saying that global warming would be even worse if it were not for the pure coincidence of simultaneous solar events does not mean that it’s not already fairly bad. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [June 15, 2017, 6:27pm UTC](https://boards.straightdope.com/t/climate-change-questions/789010/10 "2017-06-15T18:27:55Z")
> [@am77494](#): > > I am a believer in Climate Change, however most models are partially validated and their prediction capabilities are in infancy. And that is why scientists do not rely just on models to report what it is likely to happen. They use paleo records and the sea levels that the earth had when CO2 levels were high before due to natural factors. > **[Study of past warming signals major sea level rise ahead](https://phys.org/news/2017-01-major-sea.html)** > > Scientists who study patterns of natural shifts in the Earth's climate said Thursday they have uncovered a "worrisome" signal that major sea level rise could be on the way. Of course the **complete effect** of the increase of the CO2 is expected to appear in hundreds or thousands of years, but the evidence available shows that before the oceans rise 6 to nine meters over the current levels, the acceleration observed points to a “rapid” surge of about 2 meters by the end of the century. In the meantime even a third of that by mid century is not going to make things easy. And then of course I do not think history will stop on 2100, the point is that if no concerted effort is made much more ocean rise will come after that. Nowadays, humans are the ones releasing most of that CO2 into the atmosphere and the cap ice does not care about models, it is melting thanks to the warming that CO2 and other gases in the atmosphere cause. > **[Time-lapse proof of extreme ice loss](https://www.ted.com/talks/james_balog_time_lapse_proof_of_extreme_ice_loss)** > > Photographer James Balog shares new image sequences from the Extreme Ice Survey, a network of time-lapse cameras recording glaciers receding at an alarming rate, some of the most vivid evidence yet of climate change. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [June 15, 2017, 6:40pm UTC](https://boards.straightdope.com/t/climate-change-questions/789010/11 "2017-06-15T18:40:31Z")
> [@puddleglum](#): > > 1. The pyramids are just big stacks of rock, they do not need maintenance. Nothing will happen to them. Other monuments might get covered with sand if they are not maintained. > 2. In terms of ocean levels, the guesses are around 1,000 years. > 3.Rotterdam has built a surge barrier, as has Venice, and New Orleans. It can be done. Of course that guess depended on really, really really slow processes observed before. And of course in the far past the end result also took longer, the rate of change observed now (not modeled) is not likely to help. We reached more than 400PM of CO2 in the atmosphere in record time. The ocean rise is lagging, but catching up. [https://www.washingtonpost.com/news/energy-environment/wp/2016/03/3/antarctic-loss-could-double-expected-sea-level-rise-by-2100-scientists-say/](https://www.washingtonpost.com/news/energy-environment/wp/2016/03/3/antarctic-loss-could-double-expected-sea-level-rise-by-2100-scientists-say/) > [@](#): > > Sea levels could rise nearly twice as much as previously predicted by the end of this century if carbon dioxide emissions continue unabated, an outcome that could devastate coastal communities around the globe, according to new research published Wednesday. > > The main reason? Antarctica. > > Scientists behind a new study published in the journal Nature used sophisticated computer models to decipher a longstanding riddle about how the massive, mostly uninhabited continent surrendered so much ice during previous warm periods on Earth. They found that similar conditions in the future could lead to monumental and irreversible increases in sea levels. If high levels of greenhouse gas emissions continue, they concluded, oceans could rise by close to two meters in total (more than six feet) by the end of the century. The melting of ice on Antarctica alone could cause seas to rise more than 15 meters (49 feet) by 2500. > [@](#): > > The new study challenges that reasoning. It also emerges as mounting research has pointed at one region of Antarctica in particular — the Amundsen Sea sector of remote West Antarctica, centered on the enormous, marine-based Thwaites glacier — as particularly vulnerable. > > If the projections in Wednesday’s study prove correct, they could present especially bad news for U.S. coasts. The reason is gravity: Antarctica’s enormous mass pulls the ocean toward it, and when it loses significant mass, seas would surge back toward the opposite end of the world. > > “Sea level rise is not going to be felt evenly over the surface of the Earth. It’s really bad for New York, Boston. We are sort of in the bullseye,” DeConto said. As for making barriers, not all places can use them. [https://thinkprogress.org/scientist-miami-as-we-know-it-today-is-doomed-its-not-a-question-of-if-it-s-a-question-of-when-3b3212be388d](https://thinkprogress.org/scientist-miami-as-we-know-it-today-is-doomed-its-not-a-question-of-if-it-s-a-question-of-when-3b3212be388d) > [@](#): > > Even worse, South Florida sits above a vast and porous limestone plateau. “Imagine Swiss cheese, and you’ll have a pretty good idea what the rock under southern Florida looks like,” says Glenn Landers, a senior engineer at the U.S. Army Corps of Engineers. This means water moves around easily — it seeps into yards at high tide, bubbles up on golf courses, flows through underground caverns, corrodes building foundations from below. “Conventional sea walls and barriers are not effective here,” says Robert Daoust, an ecologist at ARCADIS, a Dutch firm that specializes in engineering solutions to rising seas. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [June 15, 2017, 6:47pm UTC](https://boards.straightdope.com/t/climate-change-questions/789010/12 "2017-06-15T18:47:57Z")
> [@md2000](#): > > I’m a bit of a skeptic on global warming. Check the latest sunspot data, and we seem to be heading to a global low and another little ice age. We’re also due for a real ice age anytime in the next millennium or three. What humans can do is paltry compared to mother nature. What **Chronos** said. The best evidence out there points that, in this case humans are doing more than mother nature. > **[Are Volcanoes or Humans Harder on the Atmosphere?](https://www.scientificamerican.com/article/earthtalks-volcanoes-or-humans/)** > > Does one major volcanic eruption generate more climate-altering gas than that produced by humans in their entire history? > [@md2000](#): > > However, pretending that dumping huge amounts of CO2 in the atmosphere and ignoring the consequences because “we can’t be sure” is certainly not a clever move. There’s only one way to find out for sure what will happen, and is it a good idea to try to find out? Indeed. ---
**Author:** ![Slash1972](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/slash1972/32/6461_2.png) [@Slash1972](https://boards.straightdope.com/u/Slash1972)\ **Post date:** [June 15, 2017, 6:59pm UTC](https://boards.straightdope.com/t/climate-change-questions/789010/13 "2017-06-15T18:59:37Z")
Are there any sites that show what the best case scenario and worst case scenario of climate change will be in 20 years if nothing is changed between now and then? ---
**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\ **Post date:** [June 15, 2017, 8:22pm UTC](https://boards.straightdope.com/t/climate-change-questions/789010/14 "2017-06-15T20:22:25Z")
The problem isn’t the worst case in 20 years. That’s easy to handle. Worst case in 20 years is hotter temperatures and stronger and more unpredictable storms, and extreme weather events that used to occur on average of once every hundred years happening every decade. The problem is that we’ll have dumped even more CO2 into the atmosphere in the next 20 years, which means higher average temperatures which means higher sea levels. If we continue on for 20 years that means it will take even more drastic reductions in emissions just to get back to the levels of 2017. If you’ve had your foot jammed on the accelerator for 100 years slightly backing off the accelerator doesn’t mean you start to slow down, it means you’re still going faster and faster, just not as much faster and faster. ---
**Author:** ![hibernicus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hibernicus/32/2802_2.png) [@hibernicus](https://boards.straightdope.com/u/hibernicus)\ **Post date:** [June 15, 2017, 9:12pm UTC](https://boards.straightdope.com/t/climate-change-questions/789010/15 "2017-06-15T21:12:46Z")
> [@Reddy\_Mercury](#): > > 1. Can Sea-Walls potentially save coastal cities such as New York, New Orleans, Venice, and coastal countries such as Italy and Ireland, or are they going to be lost forever? Italy and Ireland are both quite bumpy and would not be lost forever under any conceivable climate-change scenario. But our coastal cities could be in trouble. ---
**Author:** ![igor\_frankensteen](https://avatars.discourse-cdn.com/v4/letter/i/839c29/32.png) [@igor\_frankensteen](https://boards.straightdope.com/u/igor_frankensteen)\ **Post date:** [June 15, 2017, 9:18pm UTC](https://boards.straightdope.com/t/climate-change-questions/789010/16 "2017-06-15T21:18:49Z")
> [@Reddy\_Mercury](#): > > If you accept Climate Change, you know > > 1. Africa and the Middle East will be uninhabitable > > 2. Many coastal cities and countries will be underwater, lost forever. > > My questions are: > > 1. What will happen to the great monuments of history in Africa and the Middle East such as the Pyramids post Climate Change? > > 2. How long will it take for the effects of Climate Change to wear off - to go back to say, today’s current climate as the ‘norm’? > > 3. Can Sea-Walls potentially save coastal cities such as New York, New Orleans, Venice, and coastal countries such as Italy and Ireland, or are they going to be lost forever? Sorry, I completely disagree with this opening assertion. Those specifics are NOT inherent to any belief that climates change. ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [June 15, 2017, 9:38pm UTC](https://boards.straightdope.com/t/climate-change-questions/789010/17 "2017-06-15T21:38:39Z")
All those coastal, urban areas are strongholds of Democratic voters. So it seems that doesn’t matter to this government. Look at New Orleans. After President Bush’s failures with Hurricane Katrina, the population of New Orleans was dispersed. And much of it has never returned – especially the poor, who vote Democratic. This has greatly enhanced Republicans in office in the state of Louisiana. If rising seas covered the New York City area, then upstate New York voters would control the state – and all of its’ electoral votes. Same for California without its coastal voters. Real win for Republicans. Edit: whoops – maybe this doesn’t belong in GQ. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [June 15, 2017, 9:42pm UTC](https://boards.straightdope.com/t/climate-change-questions/789010/18 "2017-06-15T21:42:02Z")
> [@md2000](#): > > Check the latest sunspot data, and we seem to be heading to a global low and another little ice age. I can tell you this bit is incorrect. The “little ice age” in Europe did roughly correspond with the Maunder Minimum, but it was likely a local effect and not a global climate effect, and it’s also unclear whether this is a coincidence or causal relationship. The solar output doesn’t change enough with sunspot activity to explain the “little ice age.” ---
**Author:** ![Slash1972](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/slash1972/32/6461_2.png) [@Slash1972](https://boards.straightdope.com/u/Slash1972)\ **Post date:** [June 15, 2017, 11:28pm UTC](https://boards.straightdope.com/t/climate-change-questions/789010/19 "2017-06-15T23:28:24Z")
> [@Lemur866](#): > > The problem isn’t the worst case in 20 years. That’s easy to handle. Worst case in 20 years is hotter temperatures and stronger and more unpredictable storms, and extreme weather events that used to occur on average of once every hundred years happening every decade. > > The problem is that we’ll have dumped even more CO2 into the atmosphere in the next 20 years, which means higher average temperatures which means higher sea levels. If we continue on for 20 years that means it will take even more drastic reductions in emissions just to get back to the levels of 2017. > > If you’ve had your foot jammed on the accelerator for 100 years slightly backing off the accelerator doesn’t mean you start to slow down, it means you’re still going faster and faster, just not as much faster and faster. I’m fairly certain I didn’t say the worst case is 20 years is the problem. My question was - Are there any cites that show the best and worst cases 20 years from now if we do nothing regarding climate change? You say “hotter temperatures” but how hot? what is the best and worst case scenarios of sea level change 20 years from now if we doing nothing regarding climate change. Any cites on that? If there are no cites that show anything in that small of a time frame, what about 50 years? Any cites showing best and worst case scenarios regarding temperature, storm patterns, and/or sea level 50 years from now if we do nothing more than we are doing now to combat climate change? ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [June 15, 2017, 11:51pm UTC](https://boards.straightdope.com/t/climate-change-questions/789010/20 "2017-06-15T23:51:29Z")
> [@Slash1972](#): > > I’m fairly certain I didn’t say the worst case is 20 years is the problem. My question was - Are there any cites that show the best and worst cases 20 years from now if we do nothing regarding climate change? You say “hotter temperatures” but how hot? what is the best and worst case scenarios of sea level change 20 years from now if we doing nothing regarding climate change. Any cites on that? > > If there are no cites that show anything in that small of a time frame, what about 50 years? Any cites showing best and worst case scenarios regarding temperature, storm patterns, and/or sea level 50 years from now if we do nothing more than we are doing now to combat climate change? > **[A Glimpse at Our Possible Future Climate, Best to Worst Case Scenarios](https://skepticalscience.com/climate-best-to-worst-case-scenarios.html)** > > Recently there has been widespread discussion that perhaps the Earth's climate is not quite as sensitive to increasing atmospheric CO2 as climate scientists previously believed, which would be good news, because it would give us more time to reduce... > [@](#): > > Some adverse impacts are expected by the time we reach 1.5°C surface warming above pre-industrial temperatures. For example, widespread coral mortality, hundreds of millions of people at risk of increased water stress, more damage from droughts and heat waves and floods, and increased species extinction rates. However, by and large these are impacts which we should be able to adapt to, at a cost, but without disastrous consequences. > > Once we surpass 2°C (which is internationally considered the “danger limit” beyond which we should not pass), the impacts listed above are exacerbated, and some new impacts will occur. Coastal flooding will impact millions of people. Coral bleaching will be widespread (exacerbated by ocean acidification), most coral reefs may not survive (Frieler et al. 2012, Kiessling et al. 2012), global food crop production will decline, and sea levels will rise by close to 1 meter by 2100. Up to 30% of global species will be at risk for extinction. > > At 3–4°C warming, widespread coral mortality will occur (at this point corals are basically toast), and 40–70% of global species are at risk as we continue on the path toward the Earth’s sixth mass extinction. Glacier retreats will threaten water supplies in Central Asia and South America. The possibility of significant releases of CO2 and methane from ocean hydrates and permafrost could amplify global warming even further beyond our control. Sea level rise of 1 meter or more would be expected by 2100, with the possibility of destabilization of the Greenland and West Antarctic ice sheets, which would cause much more sea level rise and flooding of coastal communities. > > For further details, see our post here and the Point of No Return report (pages 23–25) by Ecofys and Greenpeace. To summarize, we do not want to exceed 2°C warming above pre-industrial levels (even that amount of warming is very risky), and 3–4°C or more puts us at serious risk of catastrophic climate change. Now let’s examine when we can expect to reach these temperatures in various climate sensitivity and greenhouse gas emissions scenarios. > Representative Concentration Pathways (RCP) Scenarios > > The Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report will begin to use the Representative Concentrations Pathway (RCP) scenarios. Four scenarios have been developed, and named after the radiative forcing (global energy imbalance) caused by human emissions around the year 2100. > > ``` > RCP 3-PD represents a very aggressive scenario, with a peak radiative forcing at about 3 Watts per square meter (W/m²) before 2100, declining thereafter (for perspective, a doubling of CO2 will cause about a 3.7 W/m² global energy imbalance). After peaking in 2020, our annual CO2 emissions decline at a rate of around 3.5% per year. In this scenario, our emissions actually become negative after about 2070, meaning we remove more CO2 from the atmosphere than we add. > > RCP 4.5 and RCP 6 represent global energy imbalances of 4.5 and 6.0 W/m², respectively, and stabilization without overshoot after 2100. > > RCP 8.5 represents a rising radiative forcing pathway leading to 8.5 W/m² in 2100, continuing to rise thereafter. > > ``` Point being that no serious researcher is advising that we should do nothing. The likelihood of avoiding the higher temperatures and more climate disruption by doing nothing is not much in the cards. And it has to be noted that the current lukewarmers out there are not seeing the results they expected to allow them to claim that we should expect little effects for doing nothing. Some even delete their misguided efforts from the recent past expecting many now to be fooled. Sadly, they are right. > **[Lukewarmerism, a.k.a. Ignoring Inconvenient Evidence](https://skepticalscience.com/lukewarmerism-aka-ignoring-inconvenient-evidence.html)** > > In the context of global warming, the term 'lukewarmers' refers to individuals who accept the scientific reality that human greenhouse gas emissions are a primary cause of the current global warming, but who believe that future global warming and the... [Next page](https://boards.straightdope.com/t/climate-change-questions/789010.md?page=2)